1. Field of the Invention
The present invention relates to alcoholic foam compositions.
2. Discussion of the Background
Disinfectants are used to combat pathogenic microorganisms such as bacteria, viruses, spores, fungi, etc. The use of disinfectants is unavoidable in many regions or the use is expressly required by the legislators in many countries.
Disinfectants are usually classified according to their area of application and, depending on intended use, a distinction is made between antiseptics for wound, skin, stools and sputum disinfection as well as instruments disinfection, laundry and surface disinfectants, and especially also skin and hand disinfectants.
The area of application of the aforesaid disinfectants is medically indicated and they are used for prevention of infections in hospitals, doctors' and dentists' offices, in public areas such as schools, kindergartens, nursing institutions, retirement homes, sanatoriums, etc., and also in sports facilities and other places in which infections can be transmitted. Besides the use of disinfectants in the food industry and pharmaceutical industry, they are in general use not only at the workplace or in the home, but also in service industries such as laundries and kitchens, where the products are delivered directly to patients or consumers.
Demonstration of the effectiveness of such disinfecting agents for one or more of the aforesaid areas of applications is achieved by thorough testing of these agents on the basis of standardized test methods, such as the guidelines of the German Association for Hygiene and Microbiology (DGHM) in Germany or the guidelines of the French Association for Standardization (AFNOR) in France. Examples of further standards are listed below:
DIN EN 1040Chemical disinfectants and antiseptics (basic test)DIN EN 1276Chemical disinfectants and antisepticsBactericidal action in the fields of foods, industry,home and public institutionsDIN EN 1499Disinfecting hand washingDIN EN 1500Hygienic hand disinfectionDIN EN 12054Chemical disinfectants and antisepticsProducts for hygienic and surgical hand disinfectionand hand washing - bactericidal effectDIN EN 12791Surgical hand disinfectantsAFNOR T 72 300Bactericidal effectiveness of antiseptics anddisinfectants that are employed as liquid mixed inwaterAFNOR T 72 170Bactericidal effectiveness in the presence of interferingsubstancesNF EN 1040Bactericidal effectiveness of antiseptics and chemicaldisinfectantsNF EN 1275Fungicidal effectiveness of antiseptics and chemicaldisinfectants
In the capacity of pharmaceuticals, antiseptics are further subject to legally governed approval and registration procedures.
For example, as can be seen from German Patent DE 4328828 A, various methods are available for achieving hand disinfection. Explicitly mentioned therein are the alcoholic hand disinfection methods that are standard in Germany as well as the scrub methods of hand disinfection. Products intended for hand disinfection among other purposes must satisfy at least the minimum requirements indicated in the aforesaid standards if they are to be certified as conforming with those standards and included as preparations in the disinfection list of the DGHM.
Commercially available disinfectants, especially skin and hand disinfectants, are usually composed of alcohol or mixtures of alcohols, optionally of active ingredients, which remain on the skin after evaporation of the alcohol components and which can be, for example, nonvolatile antimicrobial substances and/or common skin-care substances, and possibly other auxiliaries. If the alcohol component is used alone as the antimicrobial agent, the alcohol concentration in the product is to be chosen such that a disinfectant effect is assured even after evaporation of part of the alcohol. In this connection, it is known that this is the case for ethanolic compositions having an alcohol concentration of at least 52 wt %.
To address the disadvantages of alcoholic disinfectant solutions applied for skin and hand disinfection, thickeners have been added to such disinfectant solutions in order to increase the viscosity of these agents. Disadvantages include especially the difficulty of dosing due to the fact that the needed quantity of disinfectant often cannot be distributed uniformly over the skin or the hands and that aqueous alcohol solutions drip very easily from the hands. An example for added thickeners is found in European Patent EP 0604848 B, wherein the subject matter is a fast-drying disinfectant composition. As thickener there is described a combination of carboxyvinyl polymers and hydroxypropylmethylcellulose, wherein the total weight of the two components in the disinfectant composition is not greater than 3 wt %.
Also known are antimicrobial alcoholic gel compositions for skin and hand disinfection containing moisturizers and skin-care substances, as described in, for example, U.S. Pat. No. 4,956,170. In these compositions, cross-linked partly neutralized or neutralized acrylic acid polymers are used as thickeners. The antibacterial agent used in these compositions is 60 to 75 wt % of alcohol such as ethanol, isopropyl alcohol or mixtures thereof. Regarding the emollients contained in these gel compositions, especially petrolatum and other mineral-oil products that can be used in cosmetic preparations, as well as further hydrophobic constituents that can be used safely not only in cosmetics but also in disinfectants, it has been found that the use of such constituents in alcoholic gel compositions having high alcohol concentrations is highly detrimental to the stability of such gels, because the gels lose their viscosity and therefore their stability in the course of time during storage, and the compositions deliquesce. In general, it has been found that the gel stability suffers with increasing alcohol concentration, especially at alcohol concentrations higher than 60 wt %.
Such high alcohol concentrations, especially in gel compositions containing alcohol as the sole active component, are unavoidable, however, in order that such agents can also be certified as disinfectants for hand disinfection.
German Patent DE 10132382 discloses a simple, economic production method for the production of stable disinfectant hand-care and skin-care gels having high alcohol concentration, permitting the production of disinfectant hand-care gels that contain care components, that satisfy the standards
DIN EN 1499Disinfecting hand washingDIN EN 1500Hygienic hand disinfectionamong others directly without further additional antimicrobial adjuvants, and that also have a hepatitis B activity. Although it has been shown that the application of a disinfectant agent in gel form is to be preferred to the application of a disinfectant agent in liquid form, especially as regards its drying-out tendency, such disinfectant alcoholic gel compositions nevertheless have the disadvantage that they must lose their gel structure upon being applied on the skin, in order to ensure uniform wetting of the skin areas and thus a safe disinfectant action.
Also known are alcoholic cleaning foam compositions, which are dispensed by commercially available pump-foam systems, which are to be found mainly in sanitary units of hospitals, doctors' and dentists' offices, schools, kindergartens and nursing institutions, such as old-age homes, sanatoriums, etc. The alcohol concentration of such foam compositions is only around 40 wt %, however, because the instability of the foams increases at higher alcohol concentrations. This can also be regarded as the reason why the advantageous form of application by means of foam, which is even more manageable than alcoholic gels, has not yet been considered for disinfectants, especially not for skin and hand disinfection, because of the low alcohol concentration of the products that have been commercially available heretofore.